A major goal in efforts to understand the mechanisms by which signal transduction pathways regulate programs of gene expression is to identify their target genes and to determine the specific components of the transcriptional machinery that are recruited to these genes in response to hormonal signals. The DERC Genomics Core Facility will provide two complementary services to advance these efforts; conventional cDNA microarray analysis and recently developed promoter microarray analysis. Conventional microarray analysis will utilize glass slides spotted with PCR products corresponding to specific genes, allowing large-scale assessment of relative levels of gene expression. These arrays are intended to complement the use of commercially available microarrays (e.g., Affymetrix microarrays). For example, microarrays containing a few hundred to a few thousand cDNA targets of particular interest can be printed at relatively low cost, allowing multiple experimental conditions to be examined that would be prohibitively expensive using Affymetrix arrays. Microarrays for several organisms are currently available, including human and murine gene microarrays. Recent progress in combining the use of chromatin immunoprecipitation (CHIP) assays with DNA microarrays has recently allowed genome-wide analysis of transcription factor localization to specific promoter sequences in living cells. The DERC Genomics Core Facility will fabricate a human and murine promoter microarrays to allow genome-side location analysis of transcription factors such as nuclear hormone receptors and signal-dependent transcription factors. The fabrication of a murine promoter array will be a unique resource, and allow full exploitation of genetically engineered mouse models and cell lines.